Bleeding Bonnet Mushrooms

(Mycena haematopus) Infected by Spinellus fusiger

Cold Forest

A quiet corner of the northern woods where the Bleeding Bonnet (Mycena haematopus) thrives.
Even here, life gives way to life — a fungus consumed by another, framed in still air and soft light.

Day 1 – Early Infection

Bleeding Bonnet — Day 1, Early Infection
Fine hyphae appear around the intact caps, marking the onset of mold colonization.
The Bleeding Bonnet caps show early colonization. Fine hyphae are visible around the caps, but the structure of the mushrooms remains intact. • Size: 6000×4000

Camera: Canon EOS 5D Mk IV
Lens: EF100mm f/2.8L Macro IS USM
Settings: ISO 8000 • Aperture f/13.0 • Shutter 1/50 s

Overview

These delicate Bleeding Bonnet mushrooms were photographed over three consecutive days, capturing the progression of an infection by the parasitic mold Spinellus fusiger — also known as the pin mold fungus. The series vividly illustrates how this fast-growing mold colonizes small mushrooms, forming a halo of fine white hyphae and spore-bearing sporangia that resemble tiny pins.

Bleeding Bonnet species are common wood decomposers, often found in damp forests on fallen logs or decaying bark. While beautiful on their own, the presence of Spinellus fusiger turns them into a striking natural study of fungal parasitism — a fungus growing on another fungus.

The Infection Process

Spinellus fusiger begins as microscopic hyphae that invade the surface tissues of the mushroom’s cap. Within hours, the infection spreads, and the hyphae emerge as visible, hair-like filaments that radiate outward. By the second day, these filaments develop bulbous sporangia at their tips — structures that release thousands of spores to infect new hosts.

This process doesn’t immediately destroy the Bleeding Bonnet fruiting bodies but quickly halts their spore production, diverting the mushroom’s nutrients toward the invading mold.

Day 2 – Expansion

Bleeding Bonnet — Day 2, Extensive Mold Growth
Long translucent hyphae radiate outward, giving the caps an ethereal halo.
By the second day, the Spinellus mold has spread extensively. The translucent filaments catch the light, making this stage the most photogenic — a delicate balance of life and decay. • Size: 6000×4000

Camera: Canon EOS 5D Mk IV
Lens: EF100mm f/2.8L Macro IS USM
Settings: ISO 200 • Aperture f/22.0 • Shutter 4.0 s

Day 3 – Collapse

Bleeding Bonnet — Day 3, Collapse
The hyphae thicken and the caps begin to shrink as nutrients are consumed.
The mushrooms begin to collapse as nutrients are exhausted. The hyphae are dense, and the caps start to shrivel, marking the end of the visible infection cycle. • Size: 6000×4000

Camera: Canon EOS 5D Mk IV
Lens: EF100mm f/2.8L Macro IS USM
Settings: ISO 200 • Aperture f/18.0 • Shutter 15.0 s

Notes

• Location: [Ritter Farm Park, Lakeville, MN]
• Dates Taken: [Three consecutive days – e.g., June 5–7, 2025]
• Camera Details: (EXIF information already recorded in metadata)
• Lighting: Natural diffused light, shaded woodland.

Interesting Facts

• Spinellus fusiger is an obligate parasite of small mushrooms, especially Bleeding Bonnet, Galerina, and Coprinellus species.
• The genus Bleeding Bonnet includes over 500 species, many bioluminescent — such as Bleeding Bonnet chlorophos and Bleeding Bonnet haematopus.
• This relationship between two fungi is an example of mycoparasitism, a relatively rare but visually spectacular ecological interaction.
• The Spinellus fusiger fibers make these Mycena almost glow. Mycena chlorophos has a distingly tropical range. The Phillipines is one of the best places to see it glowing naturally.

Gallery Summary

Day	Description	Image
1	Early stage; fine hyphae beginning to emerge
2	Peak colonization with radiating hyphae
3	Mushrooms collapsing under infection